Yes, 23k acres burned in the Palisades fire, and 15k in the Eaton fire. Yes that's a lot of area compared to SF, Manhattan, etc. Most of that area is mountainside! There's not suddenly 50 square miles of open space in LA to remake in the image of some ideal.
Of the portion of heavily burned land that was developed, quite a bit was also mountainside, or at least foothill. There's ~25 regular-ish blocks of the villages (backed up against foothill) that were destroyed, and some flat-ish area on Sunset Mesa, and the west side of Temescal Canyon, and a bit on Castellammare (but thankfully that wasn't as heavily impacted). But as the names implies, these are all mesa/ridge tops, bracketed by cliffs & canyons. The impacted parts of Altadena are a bit more regular, but very much sloping foothill backed up against their own mountainside. Moreover, both areas are somewhat peripheral, even for the city-without-a-center.
The point being that these are not places one can casually lay out some expansive transit-oriented scheme that's going to solve housing problems for the city. They're topographically and geographically constrained, and need to be rebuilt in a way that's compatible with their constraints. To say nothing of the fact that these were people's homes, and are people's property, and they might have a say on how they would like to rebuild.
There are some real challenges facing LA w.r.t. family-size rental/affordable housing stock, insurance in fire-prone areas, insurance generally depending on state policy, etc. I hope the civic and political energy leveled against barriers to rebuilding in Altadena and the Palisades can later be focused on ongoing transit expansion and associated higher-density development, infill, etc, in the parts of the city where those make sense. But to pretend that these fires present some great opportunity to 'remake' Los Angeles as a whole is a misunderstanding at best, reductive and insulting at worst.
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